To maximize efficiency and minimize emissions, ship power systems are transforming from the conventional to more sophisticated power systems, such as battery hybrid-, fuel cell hybrid-, onboard DC-, and fully battery electric power systems. However, such power systems also add up the complexity in the ship systems due to different power system configurations and utilization philosophies. Besides, the real power system consists of several components onboard a vessel to make itself a complex system. For research and development, engineering, and training of such complex system requires a realistic simulator system. Therefore, this work intends to develop and demonstrate a full-scale simulator for a battery-based hybrid power system in a shuttle tanker with an industrial approach. The developed simulator simulates both physical processes onboard a vessel and their control systems and represented in process mimic diagrams (PMDs) and integrated automation system (IAS) pictures, respectively. IAS represents a real control station located at the engine control room. The complete simulator is developed integrating the dynamic component models and control system models. The dynamic component models are developed based on the first principles with varying fidelity. Majority of the required models are previously developed and are available in the inhouse model library. However, in this work, physics-based battery systems, DC grid, grid converters and their control counterparts such as battery management-, energy management system are newly developed. The ship owners and operators benefit from the full-scale simulator both during the ship design and the operation phases. Firstly, simulator can be used to simulate the what-if scenarios onboard a vessel. The ship operators can simulate a scenario which they are encountering or going to encounter soon. From the simulator results, they can observe, understand, and analyze the outcome of such scenario. It helps them making the informed decision for safe and efficient operation. Secondly, the full-scale simulators including the control system can also be used in virtual prototyping of the ship system. During the ship design phase, simulator can be used to evaluate the choice of right producers to meet power system requirements in both intact and worst-case single failure (WCSF) conditions. This helps in effective ship designing and reducing CAPEX. Power and energy management system (PEMS) needs to ensure effective use of energy carriers (engine generator sets and energy storage systems) and energy consumers (propulsion system and heavy consumers) for the safe, stable, and efficient operation. As the considered vessel falls under dynamic position (DP) class 2 category, PEMS needs to manage WCSF in different power system configurations such as two-, three-, and four split configurations. In this paper, the simulator will be used to simulate the use of battery systems in different loading conditions including peak-shaving and zero-emission operations. It also discusses the effective use of grid converters to help stabilizing the AC system. In addition, the failure scenarios leading WCSF conditions will be simulated to assess PEMS ability in managing such scenarios.